A complete bed unit consists of a bed carrying frame, a box spring assembly mounted on the frame and a mattress supported on the box spring unit. A bed carrying frame consists essentially of a pair of side rails and a pair of end rails which are connected to the side rails so that they can be folded or disassembled for shipment and storage and assembled with the side rails at the bedsite so as to form a rectangular support for the box spring assembly. The usual bed frame that is available commercially is either difficult to assemble, difficult to fold up and ship, or is of a somewhat filmsy construction when assembled. Others are unduly costly to manufacture and others are difficult to adjust to fit various size box spring assemblies. It is an object of the present invention, therefore, to provide an improved bed carrying frame which is readily foldable for shipping and storage purposes, is easily assembled to a rigid rectangular form and is readily adjusted in size to support box spring assemblies of various sizes.